Beads can be strung with an ordinary needle. The size of the bead bore (hole) determines the proper needle size. To keep loose beads under control as you work, place them on a scrap of velvet or other napped fabric.
The cording should be thin enough to pass twice through the bead bore.
Dental floss makes a durable cording. For a choker-style necklace or a bracelet, use shirring elastic.